Lamp-shade for road-vehicles.



PATENTED JULY 2, 1907.

Nog'ss'asa.

K. Hl EVANS. LAMP SHADE FOR ROAD VEHICLES.

Anmouroxrrun rms. se; 1901.

KOBYM N70/Mfrs UNITED sTATEs PATENT oEEIoE.

KENNETH HORSFALL EVANS, OF EXETER, ENGLAND, ASSIGNOR TO WELDHEN &BLERIOT LIMITED, OF LONDON,VENGLAND.

LAMP-SHADE FOR ROAD-VEHICLES.

Specification of Letters Patent.

Patented Juiy'e, 1907.

Application filed February 26, 1907. Serial No. 359.516.

To all 'whom 'it 'may concern:

Be it known that I, KENNETH HoRsFALL EVANs, a subject of the King ofGreat Britain, and a resident of 87 Sidwell street, Exeter, in thecounty of Devon,

5 England, engineer, have invented certain new and useful Improvementsin a Lamp-Shade for Road-Vehicles to Prevent Powerful Lamps Being aDanger to other Road-Users and to Increase Their Effective Range, ofwhich the following is a specification.

This invention relates to the lamps of road vehicles and more especiallyof motor-driven vehicles, and it has for its object to provide a devicewhereby those rays of light projected by a lamp, which would otherwisebe directed upwards at more than a predetermined small inclination tothe horizontal, will be either cut off or deflected downwards withoutinterfering with the horizontal or nearly horizontal rays, so thatpractically no rays will be permitted to diverge to a height sufficientto cause danger or annoyance by dazzling the eyes of persons lookingtowards the vehicle which carries the lamp or proceeding in a directioncontrary to that in which said vehicle is traveling.

In the accompanying drawings which illustrate the inventiondiagrammatically, Figure l represents a longitudinal vertical section ofa lamp to which the device is applied, and Fig. 2 represents a frontelevation of the device shown separately.

According to the present invention the lamp l to` which the device isapplied is provided with a shade projected either directly from theoriginal source 2 of the light or from the reflector 3 or other virtualsource, this shade being constituted by a plurality of plates 4 whichextend in horizontal or nearly horizontal planes from side to side ofthe light-emission aperture or passage with which the shade, as a whole,is coextensive.

The lower side 5 of each plate 4 is a reflecting surkface and-the upperside 6 a'blackened or non-reflecting siuface, so thatthose rays of lightwhich fall on the underside 5 of any of the plates are reflecteddownwards while those rays which fall on the upper side 6 of any of theplates are absorbed. Hence, any ray such as 7, 8 or 9 which (on beingprojected outwards which is presented in the path of the beam of light,

from its actual or virtual source) diverges upwards from the horizontalbeyond-a limit of inclination dependent on the ratio of the distancebetween adjacent plates to the width of the plates, will strike thereflecting under-surface 5 of one of the plates as at 7, S, or 9XL andbe reflected downwards therefrom, either issuing from the lamp in adownward direction as at 7b and 9b or being caught and absorbed by thenon-reflecting upper surface 6 of the next lower plate as at 8l. Similarly, any ray such as l0 or ll which (on being projccted outwards)diverges downwards from the horizontal beyond a limit of inclinationdependent on the same conditions as above stated, will strike and beabsorbed by the non-reflecting upper surface -of one of the plates as at10a, lla.

It will be obvious that of those outwardly directed rays such as 12 andI3 which proceed horizontally or nearly horizontally from the actual orvirtual source of light, none will be interfered with excepting therelatively small number which strike the rear edge of the plates 4,which should therefore be made as thin as practicable.

Preferably, the plates (which may be mounted in any convenient manner)would be of equal width and extend in parallel and equidistant planes.

Claims.

l. The combination with a lamp for a road vehicle of a device adapted toprevent rays of light outwardly directed from within the lamp divergingupwards at more than a predetermined inclination to the horizontal, saiddevice being constituted by a plurality of plates extending inapproximately horizontal planes across the path of the beam of light,each plate having a reflecting; under surface and a non-reflecting uppersurface, substantially as described.

2. A shade for a lamp for use on a road vehicle, constituted by aplurality of plates extending in approxiA mately horizontal planesacross the path of the beam of light, each plate having a reflectingunder surface and nonrefleeting upper surface, substantially as and forthe purpose set forth.

KENNETH HORSFALL EVANS.

Witnesses W. LINFORD BROWN, H. LINFORD BROWN.

